1. Field of the Invention
The invention relates to a level indicator having a support, a thick-film resistor network arranged on the support, a bow that pivots with respect to the support and carries a contact structure that produces, depending on the position of the bow, an electrical signal in the thick-film resistor network, a lever arm that is retained in the bow at a first end and having a float on its other end, said float having a seat for the lever arm, and the lever arm having a pivoting range lying in a first perpendicular plane. Level indicators of this kind are used in motor vehicle fuel tanks.
2. Prior Art
Level indicators of this general type have been part of the prior art for a long time. The float is dimensioned such that it has at least two major surfaces, by which the float pivots with respect to the lever arm to be aligned parallel to the surface of the liquid. When the fuel tank is in its normal position and the filling level is low, i.e. at the minimum deflection of the lever arm, the float is aligned with its major surfaces horizontal and hence parallel to the bottom wall of the tank. This is achieved by the fact that the bore to receive the lever arm extends through the center of mass of the float.
After the level indicator is mounted in the fuel tank, the level indicator must be tested and, if necessary, calibrated. For this purpose, the fuel tank is swiveled. This swiveling is used to test the maximum and minimum deflection of the lever arm of the level indicator and the electrical signals produced thereby. Since testing is carried out without fuel, it often happens that, when the tank is swiveled into the normal position, the float does not come to rest with its major surface parallel to the bottom wall of the tank. Owing to this change in the position of the float, the bore and hence the end of the lever arm are not in the position of minimum deflection, and an erroneous signal is produced as a result.
In the prior art the float is mounted on the lever arm so as to be positionally immobile. However, this has the disadvantage that a float with a shape as described at the outset strikes against the top wall of the tank before it has even reached the maximum deflection of the lever arm. In addition to the erroneous indication of the filling level, the resulting noise is troublesome.